<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta  name="viewport" content="width=device-width,user-scalable=1,initial-scale=no,maximum-scale=1.0,minimum-scale=1.0">
    <link rel="stylesheet" href="./other/myCssReset.css">
    <link rel="stylesheet" href="./bootstrap-4.6.0-dist/css/bootstrap.css">
    <title>Document</title>
    <style>
        .container{
            width: 100%;
            background-color: cadetblue;
            position: relative;
            text-align: center;
        }
        .bg1{
            
            height: 200px;
            background-image: url(./pic/item6.png);
            background-size: cover;
            box-sizing: border-box;
            overflow: hidden;
        }
        .margin1{
            padding-top: 20px;
            background-color: chocolate;
        }
        .flexbox{
            width: 750px;
            height: 600px;
            display: flex;
            margin: 0 auto;
            justify-content: space-between;
            background-color: chocolate;
            
        }
        .flexbox div{
            width:200px;
            height: 100px;
            background-color: chartreuse;
        }
       
    </style>
    <style media="print">
        #btn{
            display: none;
        }
    </style>
</head>
<body>
    <!-- <div class="container">
        <div class="flexbox">
            <div class="a"></div>
            <div class="b"></div>
        </div>
    </div> -->

    <div class="container bg1">
        <div class="row margin1">
            <div class="col-md-2 col-sm-3">扫码</div>
            <div class="col-md-5 col-sm-5">搜索</div>
            <div class="col-md-2 col-sm-3">聊天</div>
        </div>
        <div class="row">
            <div class="col-4">
                <button id="btn">点我</button>
            </div>
            <script>
                var btn = document.getElementById('btn');
                btn.onclick = function(){
                    alert('OK');
                }
            </script>
        </div>
    </div>
</body>

</html>